The methods of counters he discusses in which he defines aiki as straining hands is erroneous and is of a very limited view. Aiki has nothing at all to do with straining against a hand grab.
The critical flaw in this statement is the assumption that the author is referring to "straining against" anything when he says:
The expression "Kokyu wo ire" means "show sprit" use in 37 passages in the 147 techniques. Based on examination of these 37 passages, this expression refers to the usage of the hand blade(s) in order to break balance, and it is the same as the skill of aiki, which is, in Daito-Ryu, the skill of breaking an opponent's balance in a flash by straining hand(s).
The "straining hands" quote above is really a reflection of poor translation imho and is not an explanation of what happens when one applies Aiki in this sense. I think Josh's first post gives some insight into this. A visual representation of this concept can be found here - http://www.youtube.com/watch?v=c1QAv0FIQyE
- The video shows the application of kuzushi upon being grasped (or " the skill of breaking an opponent's balance in a flash" as said above) by utilizing tegatana in various forms. Done properly Uke does not have the choice of letting go his grasp until he is released. Most of the throws in the video are executed using Tegatana only (i.e. no grip is taken by Tori) which requires Tori to only redirect the power being given by Uke through subtle manipulation of his musculoskeletal alignment and posture.
In an article that speaks about techniques against Judo, the area of Aiki that will be most applicable will be that referring to grasps to the body (which is fundamental to the execution of Judo waza). This same concept of taking immediate total control of an attacker who grasps you on contact has been attributed to Yukiyoshi Sagawa of Daito Ryu and his own students. An example shows up in this article on Aikidojournal - http://www.aikidojournal.com/article?articleID=179
So imho there is not that much of a difference between what the article says about "straining hands" and the use of tegatana in Daito Ryu, which is what Tomiki studied under Ueshiba M. It is obvious that the article is not about various expressions and training methods of Aiki, but refers specifically to the 37 instances found in Admiral Takeshita's book - Kon.
To my own limited knowledge, Shishida Shihan has had a lot of direct contact with both Takuma Hisa and Tokimune Takeda throughout his very many years of research into Japanese Budo. He was also a direct student of Tomiki Shihan who has been and still is critical in developing many of Tomiki's ideas about Aikido and its evolution.
Personally I don't think the article does justice based on my own talks and practice with Shishida Shihan on this very subject. However I can say that I have applied the principles outlined in the article on Judoka in open randori and to date it has not failed.